Determining GPS mode of operation based upon accelerometer input

ABSTRACT

An electronic device is operable to determine a Global Positioning System (GPS) mode of operation based upon accelerometer input. The electronic device includes a communications interface, a GPS receiver, an accelerometer module, and processing circuitry. The processing circuitry receives an accelerometer output from the accelerometer module and compares the accelerometer output to a plurality of acceleration signatures. Based upon the comparison, an acceleration profile is selected. A GPS mode of operation is selected for the GPS receiver based upon the acceleration profile. The acceleration profile can be selected based upon one or more types of communications being serviced by the communications interface. In one embodiment, a selected GPS mode of operation selected corresponds to a distinct operating environment.

CROSS-REFERENCE TO PRIORITY APPLICATION

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. §120 as a continuation of U.S. Utility application Ser. No.13/113,775, entitled “Determining GPS Mode of Operation Based UponAccelerometer Input,” filed May 23, 2011, pending, scheduled to issue asU.S. Pat. No. 9,080,875, which claims priority pursuant to 35 U.S.C.§119(e) to U.S. Provisional Application No. 61/484,939, entitled“Determining GPS Mode of Operation Based Upon Accelerometer Input,”filed May 11, 2011, both of which are hereby incorporated herein byreference in their entirety and made part of the present U.S. UtilityPatent Application for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to electronic devices; and moreparticularly to electronic devices supporting Global Positioning System(GPS) operations.

2. Description of the Related Art

Communication systems are well known. Communication systems include bothwired communication systems and wireless communication systems. Wiredcommunication systems include the Public Switched Telephone Network(PSTN), Wide Area Networks (WANs), Local Area Networks (LANs), and othernetworks that use wired or optical media for the transmission of data.Wireless communication systems include cellular telephone systems,satellite communication systems, Wireless Local Area Networks (WLANs),Wireless Personal Area Networks (WPANs), and other networks that employa wireless link between a serviced terminal and a networkinfrastructure. Of course, many communications are serviced using acombination of wireless communication systems and wired communicationsystems.

Mobile navigation systems have become quite popular. Hand-held GlobalPositioning System (GPS) terminals have been available for some time andare commonly used. These hand-held GPS terminals include those that maybe mounted in an automobile, an aircraft, or a boat, and those simplycarried by a person. Many cellular telephones now have GPS receivers andsupporting applications to support GPS navigation.

Determining a GPS location is typically processing intensive. VariousGPS operational parameters must be selected based upon the use of theGPS device. For example, a GPS device servicing an airplane mustcompensate for the Doppler Effect caused by its motion. Further,navigation systems using GPS coordinates must also be customized basedupon an application. A user of a cellular telephone having a GPSreceiver typically walks for a number of steps, stops to view thesurrounding, and continues walking. The GPS navigation application mustoperate so as to accurately depict the user's location in suchoperations. Likewise, an automobile navigation system must consider thatan automobile does typically venture off-road at speed or creep intointersections. These problems must be addressed for the cellular phoneapplication even though the particular operational mode of the cellularphone is not known.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram illustrating a system constructed accordingto one or more embodiments of the present invention;

FIG. 2 is a flowchart illustrating operations of an electronic devicehaving a GPS receiver and an accelerometer module according to one ormore embodiments of the present invention;

FIG. 3 is a block diagram of an electronic device constructed accordingto one or more embodiments of the present invention;

FIG. 4 is a flowchart illustrating operations of the step of comparingaccelerometer output to acceleration signatures of an electronic deviceconstructed according to one or more embodiments of the presentinvention;

FIG. 5 is a table diagram illustrating different accelerometersignatures of an electronic device constructed according to one or moreembodiments of the present invention; and

FIG. 6 is a flowchart illustrating detailed operations of an electronicdevice having a GPS receiver and an accelerometer module according toone or more embodiments of the present invention.

DETAILED DESCRIPTION

FIG. 1 is a system diagram illustrating a system constructed accordingto one or more embodiments of the present invention. FIG. 1 showsvarious transportation modes (e.g. car 102, airplane 106, bicycle 110,motorcycle 114, boat 118, and pedestrian 124) each having an electronicdevice 104. It is understood that the present invention could apply toother modes of transportation not shown in FIG. 1, such as train, andvarious types of transportation modes, such as a fishing boat, sailboat,cruise ship as “boats”, and the like.

The electronic device 104 includes a Global Positioning System (GPS)receiver, an accelerometer module containing one or more accelerometersthat sense and measure acceleration in up to 3 axes and that is operableto produce accelerometer output. The electronic device further includesprocessing circuitry coupled to the communications interface and to theaccelerometer module. The processing circuitry is operable to comparethe accelerometer module output to a plurality of accelerationsignatures. Based upon this comparison, an acceleration profile isselected. A GPS mode of operation for the GPS receiver based upon theacceleration profile. Each electronic device 104 may also include acommunications interface that supports communications with a networkand/or other devices.

In one embodiment, the acceleration profile may be further selectedbased upon one or more types of communications being serviced by thecommunications interface of the electronic device 104. For example,cellular service is not available in airplanes or remote boating areas.In another embodiment, a selected GPS mode of operation may be selectedthat corresponds to a distinct operating environment. In anotherembodiment, the communications interface of the electronic device 104supports at least one of cellular communications, Wireless Local AreaNetwork (WLAN) communications, Wireless Personal Area Network (WPAN)communications, Satellite communication system communications, WirelessWide Area Network (WWAN) communications, millimeter wave communications,and near field communications.

In one embodiment, the processing circuitry is further operable toselect the GPS mode of operation based upon GPS location data. Forexample, the electronic device 104 may detect being over water, whichwould indicate the electronic device 104 could be in a boat or airplane,but not typically in a car or with a pedestrian. In another embodiment,the processing circuitry is further operable to select a differingacceleration profile based upon additional accelerometer output.

According to one aspect of the present invention as will be furtherdescribed with reference to the FIGs, at least one accelerationsignature comprises a periodic acceleration component and anacceleration magnitude component. For example, an acceleration magnitudediffers with various acceleration magnitudes or vibration periods, suchas a walking vibration period, car vibration period, boat vibrationperiod, train vibration period, airplane vibration period, and the like.The acceleration magnitudes are discussed in more detail herein withFIG. 5.

In one embodiment, the accelerometer output comprises data in twodimensions, and at least one acceleration signature comprises twodimensional components. In another embodiment, the accelerometer outputcomprises data in three dimensions, and at least one accelerationsignature comprises three dimensional components.

GPS navigation algorithms often use a Kalman filter to estimate positionand velocity. The Kalman Filter includes a dynamic model of the usermotion, which may be modified depending on the GPS mode of operation.Additionally, the GPS navigation algorithms typically utilize variousheuristic algorithms to detect stationary and non-stationary conditions.For example, small changes in position, especially at low velocity maybe ignored under the assumption these result from measurement noiseand/or multipath fading. The position may be said to be “clamped”. Theparameters of the heuristic algorithm, such as the amount of positionchange or velocity change before the position is “released” may bechosen based on the GPS mode of operation.

In a GPS measurement engine, tracking loops are typically utilized tofollow signals. These loops have bandwidths that may be selected basedon the GPS mode of operation. The acquisition algorithms typically haveparameters such as integration time and coherent averaging interval thatmay be selected based on the GPS mode of operation. More generally, anyparameter affecting the receiver's behavior that depends on the type ofmotion being experienced may be adjusted based on the GPS mode ofoperation.

FIG. 2 is a flowchart illustrating operations of an electronic devicehaving a GPS receiver and an accelerometer module according to one ormore embodiments of the present invention. In FIG. 2, operations 200begin when an accelerometer output of an accelerometer module of anelectronic device is determined, step 204. The accelerometer output iscompared to a plurality of acceleration signatures, step 208. Theacceleration signatures are discussed herein in greater detail in FIG.5.

An acceleration profile is selected based upon the comparison of step208, step 212. A GPS mode of operation for a GPS receiver is selectedbased upon the acceleration profile, step 214. The GPS receiver isoperated based upon the acceleration profile, step 216.

FIG. 3 is a block diagram illustrating an electronic device constructedaccording to one or more embodiments of the present invention. Theelectronic device 302 of FIG. 3 may include one or more wirelessinterfaces 304, a Global Positioning System (GPS) receiver 306,processing circuitry 308, may include one or more wired interfaces 310,and memory 312. The electronic device 302 typically would also include auser interface 314 and an audio/video interface 316. The memory 312stores data and software instructions corresponding to accelerationsignatures 318, acceleration profiles 320, and GPS modes of operation322. The wireless interfaces 304 support wireless communications betweenthe electronic device 302 and at least one other device. This wirelessinterface 304 may be consistent with a Bluetooth interface, cellularcommunications, Wireless Local Area Network (WLAN) communications,Wireless Personal Area Network (WPAN) communications, Satellitecommunication system communications, Wireless Wide Area Network (WWAN)communications, millimeter wave communications, and near fieldcommunications.

The processing circuitry 308 may include one or more of a systemprocessor, a digital signal processor, a processing module, dedicatedhardware, application specific integrated circuit, or other circuitrythat is capable of executing software instructions and for processingdata. The processing circuitry 308 is coupled to the communicationsinterface and to an accelerometer module (not shown). The processingcircuitry 308 is operable to compare the accelerometer output to aplurality of acceleration signatures 318. Based upon the comparison, anacceleration profile is selected from acceleration profiles 320. Theprocessing circuitry 308 selects a GPS mode of operation 322 for the GPSreceiver based upon the acceleration profile.

The memory 312 may be RAM, ROM, FLASH RAM, FLASH ROM, an optical memory,magnetic memory, or other types of memory that is capable of storingdata and/or instructions in allowing processing circuitry to accesssame. The wired interfaces 310 may include a USB interface, a fire wireinterface, a serial interface, a parallel interface, an opticalinterface, or another type of interface supported by a media that iscopper, metal, or optical.

The user interface 314 may include keypad, video display, cursorcontrol, touch pad, or other type of interface that allows a user tointerface with the electronic device 302. The audio/video interface 316may couple the electronic device 302 to one or more video monitors toprovide display for the GPS operations supported by the electronicdevice 302.

FIG. 4 is a flowchart illustrating operations of the step of comparingaccelerometer output to acceleration signatures of an electronic deviceconstructed according to one or more embodiments of the presentinvention. In FIG. 4, operations 400 begin when the accelerometer outputis compared to a plurality of acceleration signatures, step 402. Anacceleration signature is selected from at least two of pedestrianmotion, bicycle motion, motorcycle motion, automobile motion, trainmotion, boat motion, and airplane motion, step 404. It is understoodthat other types of motion and various versions of the transportationmodes (e.g., fishing boat, sailboat, cruise ship, etc.) may also beconsidered in the present invention.

The type of communications being serviced is detected by thecommunications interface, step 406. Based upon acceleration signatureand communication type serviced, an acceleration profile is selected,step 408. An operating environment is determined, step 410. Based uponthe determination, a GPS mode of operation is selected that correspondsto a distinct operating environment, step 412. At least one accelerationsignature comprises a periodic acceleration component and anacceleration magnitude component, step 414.

The acceleration signature table may include acceleration profiles thathave certain acceleration frequency that corresponds to differing users,e.g., pedestrian, automobile, boat, airplane, train, etc. For example,airplanes typically have a range of expected oscillation frequencies asdo boats, pedestrians, and automobiles. Based upon measured accelerationfrequency and comparison to the signatures, a positive correlation maybe determined.

Further, the table 500 may include additional signature characteristicsas well. For example, the table may include audio information that iscompared to data captured by a microphone of the electronic device.Airplanes, boats, cars, and pedestrians, for example may be exposed tounique surrounding noise, which may be used to identify the particularuse case of the electronic device. Further, the table 500 may includelocation information that is employed to identify the use case, e.g.,over water is an airplane or boat, at altitude is an airplane, etc.

The table 500 may also store accelerometer spectral characterizationsfor the differing use cases, which are employed to select the GPSoperating mode. These spectral characterizations may be pre-filtering orpost filtering; such filtering employed to improve the use caseselection process.

FIG. 5 is a table diagram illustrating different accelerometersignatures of an electronic device constructed according to one or moreembodiments of the present invention. The acceleration signature table500 of FIG. 5 shows Acceleration Signature 1 502 that corresponds toAcceleration Frequency Range 1 510, Acceleration Magnitude Range 1 520,and GPS Operating Parameters 1 530.

In FIG. 5, the Acceleration Signatures in column 1 are mode oftransportation identifiers. For example, Acceleration Signature 1 502can represent an acceleration signature of an automobile, andAcceleration Signature 2 504 can represent an acceleration signature ofa pedestrian. Acceleration Frequency Ranges of FIG. 5 are thefrequencies of acceleration and deceleration of the electronic device ofthe present invention. For example, in FIG. 5, Acceleration FrequencyRange 1 510 of an automobile would be a slower or lower frequency ofacceleration and deceleration or braking than that AccelerationFrequency Range 2 512 of a pedestrian. A pedestrian has accelerationjolts that occur at each step.

Acceleration Magnitude Ranges in FIG. 5 relate to vibration or lack ofvibration of the various modes of transportation. For example,Acceleration Magnitude Range 1 520 of an automobile having an enginevibration, vibration from tires rumbling along a roadway, and the likewould be higher than Acceleration Magnitude Range 2 522 of a pedestrianthat has no engine or other such vibration.

In one embodiment of the present invention, the processing circuitry isoperable to compare accelerometer output to a plurality of accelerationsignatures from the Acceleration Signature Table of FIG. 5. Theacceleration signatures are made up of Acceleration Frequency Ranges andAcceleration Magnitude Ranges. Based upon this comparison, anacceleration profile is selected and a GPS mode of operation or GPSOperating Parameters is selected for the GPS receiver based upon theacceleration profile. For example, in FIG. 5, the GPS OperatingParameters 1 530 would be selected instead of the GPS OperatingParameters 2 532 if the Acceleration Frequency Range and AccelerationMagnitude Range were more consistent with automobile ranges based upon acomparison of the accelerometer output (i.e., Acceleration FrequencyRange and Acceleration Magnitude Range) to other Acceleration FrequencyRanges and Acceleration Magnitude Ranges on the Acceleration SignatureTable 500.

The acceleration signature table may include acceleration profiles thathave certain acceleration frequency that corresponds to differing users,e.g., pedestrian, automobile, boat, airplane, train, etc. For example,airplanes typically have a range of expected oscillation frequencies asdo boats, pedestrians, and automobiles. Based upon measured accelerationfrequency and comparison to the signatures, a positive correlation maybe determined.

Further, the table 500 may include additional signature characteristicsas well. For example, the table may include audio information that iscompared to data captured by a microphone of the electronic device.Airplanes, boats, cars, and pedestrians, for example may be exposed tounique surrounding noise, which may be used to identify the particularuse case of the electronic device. Further, the table 500 may includelocation information that is employed to identify the use case, e.g.,over water is an airplane or boat, at altitude is an airplane, etc.

The table 500 may also store accelerometer spectral characterizationsfor the differing use cases, which are employed to select the GPSoperating mode. These spectral characterizations may be pre-filtering orpost filtering; such filtering employed to improve the use caseselection process.

The teachings of FIG. 5 are an example of an algorithm to select anacceleration profile. Classification algorithms that are well known insignal processing applications may be applied to the operations of FIG.5, such as those based on Fourier analysis of the acceleration patterns,without departing from the teachings of the present invention.

FIG. 6 illustrates more detailed operations of an electronic devicehaving a GPS receiver and an accelerometer module according to one ormore embodiments of the present invention. In FIG. 6, operations 600begin when acceleration is measured, step 602 by an electronic device ofthe present invention shown in FIG. 3 having a communications interfacethat is operable to support communications between the electronic deviceand at least one other device. The communications interface supports atleast one of cellular communications, Wireless Local Area Network (WLAN)communications, Wireless Personal Area Network (WPAN) communications,Satellite communication system communications, Wireless Wide AreaNetwork (WWAN) communications, millimeter wave communications, and nearfield communications. The electronic device comprises a GlobalPositioning System (GPS) receiver, and an accelerometer module that isoperable to produce accelerometer output. Processing circuitry iscoupled to the communications interface and to the accelerometer module.The processing circuitry is further operable to select the GPS mode ofoperation based upon GPS location data. In one embodiment, theprocessing circuitry is further operable to select a differingacceleration profile based upon additional accelerometer output.

In FIG. 6, the acceleration is compared to a first accelerationsignature, step 604, via the processing circuitry. Accelerationsignatures may correspond to pedestrian motion, bicycle motion,motorcycle motion, automobile motion, train motion, boat motion, orairplane motion. In one embodiment, at least one acceleration signaturecomprises a periodic acceleration component and an accelerationmagnitude component. According to one embodiment of the presentinvention, the accelerometer output may comprise data in two dimensions,and at least one acceleration signature comprises two dimensionalcomponents. According to another embodiment of the present invention,the accelerometer output comprises data in three dimensions, and atleast one acceleration signature comprises three dimensional components.

A determination is made regarding whether the acceleration signaturecomparison is more favorable than a current match, step 606. In oneembodiment, the acceleration profile may be further selected based uponone or more types of communications being serviced by the communicationsinterface. If No, the process repeats to steps 604 and 606, whereacceleration is compared to a next acceleration signature, step 604, andthe determination is made regarding whether the comparison is morefavorable than the current match, step 606. If Yes, the more favorablecomparison or match is selected as the most favorable match, step 608.

A determination is made regarding whether the comparisons are completed,step 610. If No, the process repeats to steps 604 and 606 whereacceleration is compared to a next acceleration signature, step 604, andthe determination is made regarding whether the comparison is morefavorable than the current match, step 606, and so forth. If Yes, aGlobal Positioning System (GPS) mode of operation is enacted, step 612.The GPS mode of operation may be selected for the GPS receiver basedupon the acceleration profile. A selected GPS mode of operation selectedmay correspond to a distinct operating environment. The terms “circuit”and “circuitry” as used herein may refer to an independent circuit or toa portion of a multifunctional circuit that performs multiple underlyingfunctions. For example, depending on the embodiment, processingcircuitry may be implemented as a single chip processor or as aplurality of processing chips. Likewise, a first circuit and a secondcircuit may be combined in one embodiment into a single circuit or, inanother embodiment, operate independently perhaps in separate chips. Theterm “chip,” as used herein, refers to an integrated circuit. Circuitsand circuitry may comprise general or specific purpose hardware, or maycomprise such hardware and associated software such as firmware orobject code.

The present invention has also been described above with the aid ofmethod steps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention.

The present invention has been described above with the aid offunctional building blocks illustrating the performance of certainsignificant functions. The boundaries of these functional buildingblocks have been arbitrarily defined for convenience of description.Alternate boundaries could be defined as long as the certain significantfunctions are appropriately performed. Similarly, flow diagram blocksmay also have been arbitrarily defined herein to illustrate certainsignificant functionality. To the extent used, the flow diagram blockboundaries and sequence could have been defined otherwise and stillperform the certain significant functionality. Such alternatedefinitions of both functional building blocks and flow diagram blocksand sequences are thus within the scope and spirit of the claimedinvention. One of average skill in the art will also recognize that thefunctional building blocks, and other illustrative blocks, modules andcomponents herein, can be implemented as illustrated or by discretecomponents, application specific integrated circuits, processorsexecuting appropriate software and the like or any combination thereof.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “coupled to” and/or “coupling” and/or includes direct couplingbetween items and/or indirect coupling between items via an interveningitem (e.g., an item includes, but is not limited to, a component, anelement, a circuit, and/or a module) where, for indirect coupling, theintervening item does not modify the information of a signal but mayadjust its current level, voltage level, and/or power level. As mayfurther be used herein, inferred coupling (i.e., where one element iscoupled to another element by inference) includes direct and indirectcoupling between two items in the same manner as “coupled to.” As mayeven further be used herein, the term “operable to” indicates that anitem includes one or more of power connections, input(s), output(s),etc., to perform one or more its corresponding functions and may furtherinclude inferred coupling to one or more other items. As may stillfurther be used herein, the term “associated with,” includes directand/or indirect coupling of separate items and/or one item beingembedded within another item. As may be used herein, the term “comparesfavorably,” indicates that a comparison between two or more items,signals, etc., provides a desired relationship. For example, when thedesired relationship is that signal 1 has a greater magnitude thansignal 2, a favorable comparison may be achieved when the magnitude ofsignal 1 is greater than that of signal 2 or when the magnitude ofsignal 2 is less than that of signal 1.

The present invention has also been described above with the aid ofmethod steps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention.

Moreover, although described in detail for purposes of clarity andunderstanding by way of the aforementioned embodiments, the presentinvention is not limited to such embodiments. It will be obvious to oneof average skill in the art that various changes and modifications maybe practiced within the spirit and scope of the invention, as limitedonly by the scope of the appended claims.

The invention claimed is:
 1. An integrated circuit comprising: a Global Positioning System (GPS) receiver interface configured to interface with a GPS receiver; an accelerometer interface configured to receive accelerometer data including acceleration frequency and acceleration magnitude; and processing circuitry communicatively coupled to the GPS receiver interface and to the accelerometer interface and configured to: receive the accelerometer data via the accelerometer interface; compare the acceleration frequency and the acceleration magnitude to respective acceleration frequency ranges and acceleration magnitude ranges of a plurality of acceleration signatures, a first of the plurality of acceleration signatures having two-dimensional acceleration components and a second of the plurality of acceleration signatures having three-dimensional acceleration components; based upon the comparison, select an acceleration profile; select a GPS mode of operation based upon the acceleration profile; and direct the GPS receiver to operate according to the selected GPS mode of operation via the GPS receiver interface.
 2. The integrated circuit of claim 1, further comprising a communications interface that is configured to support communications between the integrated circuit and at least one other device; and wherein the processing circuitry is further configured to select the acceleration profile based upon one or more types of communications that are currently serviceable by the communications interface.
 3. The integrated circuit of claim 2, wherein the one or more types of communications that are currently serviceable by the communications interface include one or more of cellular communications, Wireless Local Area Network (WLAN) communications, Wireless Personal Area Network (WPAN) communications, or Satellite communication system communications.
 4. The integrated circuit of claim 1 wherein the plurality of acceleration signatures correspond to at least two of: pedestrian motion; bicycle motion; motorcycle motion; automobile motion; train motion; boat motion; or airplane motion.
 5. The integrated circuit of claim 1, wherein a selected GPS mode of operation corresponds to a distinct operating environment.
 6. The integrated circuit of claim 1, wherein the processing circuitry is further configured to select the GPS mode of operation based upon a time of day and/or a day of week.
 7. The integrated circuit of claim 1, wherein the processing circuitry is further configured to select the GPS mode of operation based upon GPS location data received via the GPS receiver interface.
 8. The integrated circuit of claim 1, wherein the GPS receiver interface and the accelerometer interface comprise a single interface.
 9. The integrated circuit of claim 1, wherein at least one acceleration signature comprises an acceleration frequency component and an acceleration magnitude component.
 10. A method for operating an integrated circuit comprising: receiving accelerometer data including acceleration frequency and acceleration magnitude via an accelerometer interface; comparing the acceleration frequency and the acceleration magnitude to respective acceleration frequency ranges and acceleration magnitude ranges of a plurality of acceleration signatures, a first of the plurality of acceleration signatures having two-dimensional acceleration components and a second of the plurality of acceleration signatures having three-dimensional acceleration components; based upon the comparison, selecting an acceleration profile; selecting a Global Positioning System (GPS) mode of operation based upon the acceleration profile; and directing a GPS receiver to operate according to the selected GPS mode of operation via a GPS receiver interface.
 11. The method of claim 10, further comprising: communicating with at least one other device via a communications interface; and selecting the acceleration profile further based upon one or more types of communications that are currently serviceable by the communications interface.
 12. The method of claim 11, wherein the one or more types of communications that are currently serviceable by the communications interface include one or more of cellular communications, Wireless Local Area Network (WLAN) communications, Wireless Personal Area Network (WPAN) communications, or Satellite communication system communications.
 13. The method of claim 10, wherein the plurality of acceleration signatures correspond to at least two of: pedestrian motion; bicycle motion; motorcycle motion; automobile motion; train motion; boat motion; or airplane motion.
 14. The method of claim 10, wherein a selected GPS mode of operation corresponds to a distinct operating environment.
 15. The method of claim 10, further comprising selecting the GPS mode of operation further based upon a time of day and/or a day of week.
 16. The method of claim 10, further comprising selecting the GPS mode of operation based upon GPS location data received via the GPS receiver interface.
 17. The method of claim 10, wherein at least one acceleration signature comprises an acceleration frequency component and an acceleration magnitude component.
 18. An integrated circuit comprising: a Global Positioning System (GPS) receiver interface configured to interface with a GPS receiver; an accelerometer configured to produce accelerometer data including acceleration frequency and acceleration magnitude; and processing circuitry communicatively coupled to the GPS receiver interface and to the accelerometer and configured to: receive the accelerometer data; compare the acceleration frequency and the acceleration magnitude to respective acceleration frequency ranges and acceleration magnitude ranges of a plurality of acceleration signatures, a first of the plurality of acceleration signatures having two-dimensional acceleration components and a second of the plurality of acceleration signatures having three-dimensional acceleration components; based upon the comparison, select an acceleration profile; select a GPS mode of operation based upon the acceleration profile; and direct the GPS receiver to operate according to the selected GPS mode of operation via the GPS receiver interface.
 19. The integrated circuit of claim 18, further comprising a communications interface that is configured to support communications between the integrated circuit and at least one other device; and wherein the processing circuitry is further configured to select the acceleration profile based upon one or more types of communications that are currently serviceable by the communications interface.
 20. The integrated circuit of claim 18, wherein the processing circuitry is further configured to select the GPS mode of operation based upon a time of day and/or a day of week or GPS location data received via the GPS receiver interface. 